OBLIQUITIES OF KEPLER STARS: COMPARISON OF SINGLE- AND MULTIPLE-TRANSIT SYSTEMS

The stellar obliquity of a transiting planetary system can be constrained by combining measurements of the star's rotation period, radius, and projected rotational velocity. Here, we present a hierarchical Bayesian technique for recovering the obliquity distribution of a population of transitin...

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Bibliographic Details
Main Authors: Morton, Timothy D., Winn, Joshua Nathan
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:en_US
Published: IOP Publishing 2015
Online Access:http://hdl.handle.net/1721.1/92942
https://orcid.org/0000-0002-4265-047X
Description
Summary:The stellar obliquity of a transiting planetary system can be constrained by combining measurements of the star's rotation period, radius, and projected rotational velocity. Here, we present a hierarchical Bayesian technique for recovering the obliquity distribution of a population of transiting planetary systems and apply it to a sample of 70 Kepler objects of interest. With ≈95% confidence, we find that the obliquities of stars with only a single detected transiting planet are systematically larger than those with multiple detected transiting planets. This suggests that a substantial fraction of Kepler's single-transiting systems represent dynamically hotter, less orderly systems than the "pancake-flat" multiple-transiting systems.